Multivessel coronary artery bypass grafting via small thoracotomy versus sternotomy (MIST): an investigator-initiated, international, open-label, randomised controlled trial.

Summary

In this international randomized trial of 170 patients with multivessel coronary artery disease, MICS CABG through a small thoracotomy produced higher 1-month SF-36 physical component scores than sternotomy CABG, with a mean difference of 2.9 points. No deaths or strokes occurred through 12 months, although the study was conducted in selected patients and experienced centers.

Key Findings

• At 1 month, SF-36 physical component scores were 45.1 after MICS CABG versus 42.2 after sternotomy CABG, with a mean difference of 2.9 points and p=0.031.
• There were no deaths or strokes in either group through 12 months.
• The trial randomized 170 patients across seven centers in six countries and used intention-to-treat analysis with multiple imputation for missing primary outcome data.

Clinical Implications

MICS CABG should be considered for appropriately selected patients with multivessel disease when performed by experienced teams, particularly when early physical recovery is a priority. Broader implementation requires training, careful patient selection, and confirmation of long-term graft and cardiovascular outcomes.

Limitations

• The sample size was modest and the open-label design may have influenced patient-reported outcomes.
• Eligibility required suitability for both procedures, and operations were performed by experienced teams, limiting generalizability.

Future Directions

Larger pragmatic trials and registries should assess long-term graft patency, repeat revascularization, quality of life, cost-effectiveness, and outcomes across lower-volume centers and broader patient subgroups.